Camping Down Quilts are growing in popularity. They are a sleeping bag on top and bare on the bottom. The theory is that in traditional sleeping bags your weight flattens the layer underneath you, thereby reducing the effective loft and insulation anyway. Down quilts drape over the top of you and attach to your sleeping pad or mat, relying on them to provide insulation on underneath you. Quilts are zipless, reduce some of the extra bulk and cost of sleeping bags and allow greater freedom of movement and temperature regulation in warmer temps than can get in a sleeping bag.